The present invention relates to a golf ball of three or more layers, including a core, an intermediate layer and a cover, which ball has an excellent feel on impact, controllability and flight performance.
Golf club performance has been improving in recent years, one effect of which has been a significant decline in the spin rate of the golf ball after it is hit. However, the spin rate tends to remain high under the hitting conditions of the average golfer (golfers having an average score), which accounts for the majority golfers. Hence, by achieving a lower ball spin rate, there remains room for increasing the distance traveled by the ball.
Art for increasing the distance includes improvements to the material making up the intermediate layer sandwiched between the core and the cover serving as the outermost layer. For example, JP-A 2003-175130 discloses a highly neutralized intermediate layer material in which the degree to which an ionomer resin or the like has been neutralized is set relatively high.
However, in such a golf ball, the use of a soft cover is presumed. That is, the ball does not have a construction in which a hard cover is used to take full advantage of the properties of a high-resilience intermediate layer.
JP-A 2006-87948 teaches a golf ball which uses an intermediate layer material having a high degree of neutralization. Such a ball does have an improved rebound, but there remains room for improvement as a spin rate-lowering construction.
Highly neutralized intermediate layer materials have also been disclosed in, for example, JP No. 3729243, JP No. 3772252 and JP-A 2002-345999. However, in all of these disclosures, there remains room for further improvement in terms of fully exploiting the high resilience of the intermediate layer and reducing the spin rate. Moreover, these prior-art golf balls leave something to be desired not only in their distance of travel, but also in their feel on impact and their durability to cracking.